Tension mounts as the judges select the finalists to move on to live competition.

As the judges’ homes portion of The X Factor continues, the oldest and the youngest competitors step up to the mic to show judges L.A. Reid and Britney Spears what they're made of.

Joined by Justin Bieber and Scooter Braun at his Beverly Hills home, Reid asked his team to “really show me that you want it.” On Wednesday’s episode, Reid threw a bit of a fit upon finding out that he’d be mentoring the Over 25 group, beating up his phone and even telling his recruits that he was disappointed to have them. On Thursday, Reid told the audience, "I really didn't want this category. I'm known for developing young artists like Justin Bieber."

But, after hearing stellar performances from Jason Brock, Vino Alan and especially David Correy, Reid appeared to have warmed to the idea. “In the beginning I wasn’t particularly thrilled with this category,” he said. “I’m having a change of heart.”

On the so-so side were Daryl Black and Tate Stevens, while Tara Simon appeared blissfully oblivious to her pitch problems. Regardless, one of them will make it through as one of the four contestants to move onto live competition.

Bieber struggled with the idea of cutting two competitors, saying that he didn’t want to send anyone home, but snapped into reality when Reid put things into perspective. "If you had to go into your bank account and write a check for $5 million, would you give it to that guy?" Reid asked.

Meanwhile, over in Malibu, Spears selected music multihyphenate will.i.am to aid her in judging the teen group. “He has such a fresh sound and he knows what the kids are listening to,” Spears said of the Black Eyed Peas frontman.

If contestants were looking for feedback from the pop superstar, they must have been sorely disappointed. Spears only quietly clapped or murmured a sweet “thank you” following each performance, offering only a few words of evaluation to will.i.am in private. (Not to say Reid was overly talkative, but he at least engaged his mentees in a bit of banter.) As a child star growing up in the spotlight, Spears’ biggest concern seemed to be the singers' ability to stand up to the crushing pressures of showbiz.

“Very talented young girl,” Spears said of standout singer Carly Rose Sonenclare. “I’m just kind of scared that she may not be able to cope with the pressure of everything.”

Performing a stripped down version of Karmin’s “Brokenhearted,” Sonenclare wowed will.i.am, who gushed that she was a caterpillar who wouldn’t turn into a butterfly -- but a dragon.

Reed Deming struggled to swallow his nerves with the Plain White T’s “Hey There Delilah,” but Spears still believes in his potential. “I think that he could deliver a little bit better than what he did,” she said.

At this point in the game, it's hard to pick any teen to go home. Maybe it's because powerhouse vocals are made all the more impressive by their tiny frames. Spears and will.i.am picked apart minor flaws, including stage presence, control and, simply put, needing a bit of work.

If we had to guess, it would seem most likely that Reed and James Tanner go home. Reed, because he's a carbon copy of the Biebs and his nerves are still getting the best of him. James, because Spears just didn't seem that into his rapping.

But in true X Factor fashion, Reid and Spears didn't show their cards at the end of the hour. We'll have to wait for next Tuesday to find out who makes the cut.